SEAWEED RESOURCES OF SARAWAK

INTRODUCTION

Sarawak has a land area of 124,449 km˛ which represents 38% of Malaysia's land.mass with a coastline length approximately 1000
km. In general, the climate
along the Sarawak coast is tropical monsoon characterized by high temperature,
high humidity and. heavy seasonal rainfall. Long term average daily temperatures along the coast-range
from as high of 31°C to as low of 22°C, with very little seasonal variation. On the
other hand, rainfall shows considerable seasonal variation in tune with the
monsoon periods. Tidal range along the Sarawak coast is generally large, up to 6
meters. The coastal waters are enriched with nutrients leached from the land and
all this support a highly diverse flora and fauna. Among the conspicuous floras
in the coastal environment are the seaweeds.

Seaweeds are macro benthic marine algae. They form a conspicuous component of
primary producers in the shallow marine environment. They possess different type
of pigments such as chlorophylls, carotenoids, phycobilins, and other accessory
pigments which enable them to synthesize organic compound from simple compounds
such as water and carbon dioxide in the presence of light as source of energy.
Except among the blue green algae, the pigments are contained in organelles
called plastids. Chlorophyll a, the primary pigment is present in all groups
however, other chlorophyll and accessory pigments such as the phycobilin,
carotenoids may differ among the major groups. The accessory pigments may blend
or mask chlorophyll a to produce the diagnostic colour of the different groups,
thus the names green, brown, blue-green and red seaweeds originated.

As Sarawak is surrounded by warm waters on all sides and the sun shines all the
year round, seaweeds tends to grow luxuriously along the coastal areas. This
is especially so on the reef flats in Kuching Division at the southern portion
and the Miri Division at the northern portion and around most of the Kuching
Division offshore islands. Seaweeds tend to grow well in protected areas, that
is why seaweeds were found attached to the rocky beach in Pantai
Similajau (Bintulu Division-northern portion).
Meanwhile, the muddy mangrove area along Pulau Salak area support specialised
types of seaweeds of limited species.

Most seaweeds are limited in their distribution at the intertidal to the shallow subtidal zone in the marine environment although a few may be found
high in the' supratidal zone (spray zone). The difference in their distributional
pattern is reflective of their ability to adapt to the ambient ecological
condition in their habitat. Some species are found only in sheltered bays and
coves or on the reef flat with other distributed only in the rocky wave-exposed
areas along the shore or near the reef edge. The presence of the species in
certain habitat is depended on their ability to adapt to the synergistic effect
of the different of ecological factors in the environment.

It has been the intention of this study to record the seaweed resources of
Sarawak (because of the limited studies that have been done). The method adopted
was simple. Regular visits were made to various coastal areas and offshore
islands to collect specimens. The specimens were identified and preserve as
herbarium sheets. In identifying most of the seaweeds, a X 10 magnification band
lens was used. However, in microscopic forms and the identification of species
of certain microscopic forms, a compound microscope was necessary. This is
because certain microscopic characters are of specific significance. In some
cases it was necessary to take cross-sections of the thallus, and in such
instances, a sharp blade was used and the sections examined under the
microscope. AIl the herbarium was kept in Fisheries Research Institute, Sarawak
Branch, Bintawa, Kuching for display and reference.

Monthly trips were made from May 1996 to September 1996, nom April 1997 to July
1997 and May 1998 to November 1998 during low tide.

Sampling Procedure

Sampling was done randomly and the method of collection was using '(
SCUBA-diving covering islands and coral reef grounds, whereas walking along J )(
the beach method was used to collect sample at rocky/sandy beach.

Collecting and preserving seaweeds

The best time for collection was during low tide when a large expanse of the
shore was exposed. For SCUBA- Diving entailing areas like islands and coral reef
grounds, collection can be done any time as long as the water visibility is
good. When collecting at rocky beach, the trip was planned to coincide with the
hour of falling tide, particularly one to two hours before low tide, so that the
seaweeds could be observed, collected, and recorded in their natural habitat and
life position. Tide tables must be obtained in planning of collecting specimens.

In warm waters, as a manner of collecting seaweeds, trousers
should be worn to guard against cuts and scratches nom barnacles or coral, and
rubber shoes will aid movement over slippery rocks. Entire plants were collected
to make sure that the holdfast was not left out. It was relatively easy to
detach the holdfast in certain species but in others this required some effort.
In such cases a sharp instrument (like scrapping blade) was used. Samples were
collected for specific use and it was unnecessary to over-collect. Other
necessity included pails, plastic bags, label, putty knife, forceps plus hammer
and chisel for collecting crustose specimen.

When collecting at any locality has been completed, the
specimens were.either be pressed directly as fresh material (for delicate
specimen), but for coarser specimen, 4 to 5% formalin was poured into every each
plastic bags.

When collecting, attention should be paid to the less obvious
species that grow on, or under, the larger,. conspicuous plants. Small, delicate
forms were found as epiphytes on the fronds, stipes and holdfasts of large
thalli, whilst crustose taxa grew both as epiphytes on other algae and as
lithophytes on hard substrata. Some species grew only submerged in rock-pools;
filamentous forms. might bind sand . and silt nom which they must be washed
gently.

Identification of the samples collected

Identification of the samples collected was made using reference books, journals
and confirmation of the samples collected made by Professor Dr. Phang Siew Moi
from University of Malaya. All the samples collected and identified have been
preserved as herbarium. Recognition of the plants, both as they appear in nature
or as preserved specimen, was accomplished by this practice .of handling and
distinguishing .them plus reading. and understanding the ,description to
familiarize individuals to confirm the specimen collected.

How to make herbarium

The preparation of preserved specimens was begun at once, although it was
preferable to . leave it in preservative for few day~ to allow complete fixation
(for delicate specimens, herbarium should be made as soon as possible to hinder
deterioration). In processing the specimens, necessary equipment were: drawing
paper (or unglazed paper), blotting paper, muslin clot~ enamel tray (or shallow
dish), newspaper, herbarium paper, forceps, small brush, scrapping blade. The
specimen were washed in the sea water to remove sands, then, once more it was
washed using fresh water to remove excess dirt and debris using small brush,
forceps and scrapping blade to thoroughly make sure that when the specimen
dried, moulding could not take place.

The specimen was ultimately placed on standard drawing paper, mounting was done
in a flat enamel tray, large enough to accommodate the paper. The water must be
at least deep enough so as to allow the particular specimen to float and later
spreading it on the. paper. After the specimen has been spread out in the
natural manner, the sheet was lifted carefully from one side to allow the water
to drain off gradually and to leave the specimen spread out undisturbed. After
that, the mounted specimen was covered in a piece of muslin cloth, then a
blotting paper was placed on top of the muslin cloth to absorb extra water and
later the specimen was placed between newspapers. More specimen were piled with
newspapers between and slight pressure to the pile (the pressure can be books,
wooden frame etc), was provided to facilitate the drying procedures, the
newspaper was often changed, daily even twice a day depending on the specimen.
When the specimen were totally dried (small specimen took 3 days and large
specimen took 7 days), the muslin cloth was peeled off carefully, the mounted
dried specimen was then pasted onto standard -size herbarium papers. Labels
bearing date of collection, location, collection number, Family, Scientific name
of the specimen, determiner/collector and some notes were attached. This
labelling must tally with the field book, and according to alphabetical order
and stored in cabinet/cupboard for reference.

Data Analysis and Report

Data analysis was done based on samples that have been collected. The samples
have been categorized into commercial and non-commercial species which will be
arranged as inventory information on the "Seaweed resources in Sarawak".

Distribution of Seaweed in Kuching Division

Distribution of Seaweed in Bintulu Division

Distribution of Seaweed in Bintulu Division

Distribution of Seaweed in Salak Mangrove Estuary

RESULTS AND DISCUSSION

In terms of diversity, the species taxonomy composition in
Sarawak is low. One of the main factors contributing to the low diversity of
algae/seaweeds species around Sarawak is the relatively large tidal range(> 3
m). and relatively low sheltered bays and islands. The water here is turbid and
therefore light (which is essential for growth) will only penetrate to a shallow
depth (probably less than one meter). These two factors act together such that
for algae to be able to photosynthesize at high tide it must grow higher in the
intertidal region and would therefore be exposed to the air at low tide. Algae
growing. in areas. where exposure times were limited would be too deep during
high tide and unable to. photosynthesize. sufficiently to support growth.

Checklists of the marine algae of Malaysia have been published (Phang, 1984,
1986, Phang & Wee, 1991; Teo & Wee, 1983). The checklists have been based on all
available published reports and on collections made which did not include
seaweed in Sarawak.

From this study, it shows that the most abundance seaweeds in Sarawak is from
the Rhodophyta Division followed by Chlorophyta Division and Phaeophyta
Division. In terms of Division, from the Rhodophyta Division, the most abundance
seaweeds comes from the Family Gracilariaceae, whereas Chlorophyta Division, the
most dominant comes from the Family Caulerpaceae and Phaeophyta Division the
most abundance comes from the Family Sargassaceae.

In terms of locality surveyed, a more complex diversity can be seen in Kuching
Division (all the survey area covering islands and coral reef grounds). In Miri
Division, the species taxonomy composition, lies on the species that have
correlation/integration with coral reef community.

The collection of seaweed species covering rocky/sandy beach entailing Pantai
Bungai, Miri And Pantai Similajau, Bintulu indicate that Pantai Bungai has no
seaweed but in 1992 (personal observation); particularly Gracilaria grew
in this area. It could be because of erosion and the beach has been exposed to
stronger waves.

In contrast to Pantai Bungai, Pantai Similajau reveals a variety and abundance
of seaweeds, especially Gracilaria salicomia, Laurencia papillosa,
Laurencia lageniformis, Enteromorpha intestinalis and
Enteromorpha tubulosa. This area is a well protected area, and the rocky
beach is really suitable for attachment of seaweeds spore. Size comparison can
be made with the same species found on islands in Kuching.
The species in Kuching smaller compared to those in Pantai Similajau. This could
be due to favourable condition in Pantai Similajau, Bintulu.

In the mangrove areas of Pulau Salak, seaweeds Bostrychia binderi,
Dictyota friabilis, Cladophora sp., Catenella nipae can be
found in abundance. All the species have integration with mangrove community.
Here, the seaweeds bearing agar, Gracilaria changii and Gracilaria
blodgettii are found attached to mangrove tree roots, particularly,
Avicennia sp., and Rhizophora sp., and they are available throughout
the year(personal communication with fishermen in Salak). This indicates that
the seed can be obtained throughout the year. The species from floating cage
systems (owned by FRI) is dominated by Gracilaria changii, Gracilaria
edulis plus some other seaweeds like Padina minor, Sargassum
ilicifolium, Caulerpa verticillata, Acanthophora spicifera,
Bryopsis hypnoides, B. pennata and others.

From this survey, the Gracilaria can be cultured in floating cages.
Floating raft system are generally used where the water is too deep for bottom
culture or where tidal fluctuations are large ( >3 m). This is the type of
system most likely to be useful in the estuarine areas in Sarawak as recommended
by consultant for paper on seaweed resources of Sarawak: commercial, potential
and utilization by Anthony Cheshire, 1994).

CONCLUSION

From the results, the species taxonomic composition of
seaweed found are : 41 specimens from the Rhodophyta Division, 36 specimens from
the Chlorophyta Division and 28 specimens from Phaeophyta Division, plus
unidentified specimen (still with Dr. Phang Siew Moi for identification - 11
specimens) that makes the total sum of 116 species. Among them, there are two
new records that is Scinaia boergesenni (Rhodophyta Division) and
Zonaria sp., (Phaeophyta Division).

The most abundance seaweed comes from the Rhodophyta Division
and the most dominant genus are Gracilaria. In terms of culture potential
Gracilaria has been known to be a suitable candidate.

THE MAJOR CLASSES OF SEAWEEDS AND THEIR REPRESENTATIVE
SPECIES

CLASS CHLOROPHYCEAE (Green seaweed)

In the green algae, there is the predominance of the. green pigments,
chlorophylls a and b, which mask the pigment' such as carotenes, luteins, and
other Xanthophylls - zeaxanthin and siphonaxanthin. As in the other group, these
photosynthetic pigments are found in the lamellae (called thylakoids) of the
chloroplasts, which in the green algae are grouped into bands of three to seven.
Their cell wall is composed of an outer pectin layer and inner cellulose layer.

Some species have calcified walls consisting of an aragonite
form of calcium carbonate. Starch is their photosynthetic product. Reproduction
iri this group is both sexual and asexual. Asexual reproduction is by motile
(zoospores) and nonmotile (aplanospores) spores. Sexual reproduction is commonly
by motile gametes:isogametes, anisogametes, eggs and sperms. Vegetative
'multiplication' through fragmentation of the thallus is common especially among
the filamentous species. Life histories among the green algae are highly
diverse. Most members exhibit haplontic life history although diplontic and
diplohaplontic types also occur among some members.

FAMILY ACETABULARIACEAE

Acetabularia major Martens

Thalli moderately calcified up to 6 cm tall, consisting of a
slender stalk and a terminal cap, 18 mm in diameter, made up of sixty-three to
eighty-five gametangial rays laterally attached to each other by calcification;
gametangial rays cylindrical-compressed, decreasing in diameter towards the
centre of the cap, their terminal wall at the margin of the cap truncate to
slightly emarginate. Growing in colonies on rocks, shell in moderately
wave-washed habitats near shore and in shallow water.

Bushy plant attached to substrate with big holdfast (full
with rhizoids). Grows straight and alone but attached to the same holdfast. The
stipe greenish in colour and 8 - 10 cm long. Long stipe, bringing with disc apex
but some are stipes alone.

Habitat: This particular species is found together with coral
and found in 4.6 meters depth.

Local Distribution: Found in Teluk Melano, Sematan,
(01°52.5'N, 109°43'E)

[picture upon request]

FAMILY ANADYOMENACEAE

Anadyomene plicata C. Agardh

Thalli form low, caespitose greenish clumps attached to solid substrate by
rhizoidal holdfast. The clump consists of several overlapping stalked blades
with entire to undulate margins. The veins produce five to seven flabellately
divergent branches at each polychotomous, all or commonly form to five of these
develop into the main veins, the two or three at the middle usually the largest.
Common on rocks or dead corals at the intertidal to shallow subtidal areas
exposed to moderate water movement.

Plants with a rhizoidal base and a crisp cluster of flat blades, 3 - 6 cm in
height; the blades ovate to reniform in shape and one cell thick. Throughout the
blade there are single, branching filaments which form pseudoveins. The area
between the veins is filled with oval to elongate cells.

Thalli small up to 1.5 cm tall, forming dense clusters consisting of the
prostrate, terete, naked branched stolon less than 1 mm in diameter attached to
the substrate by rhizoids and erect, terete branches which are simple or
branched bearing crowded stalked spherical ramuli, 1-1.5 mm in diameter. Grow on
dead corals or coralline rocks in intertidal to shallow subtidal wave-exposed
areas on the reef.

Erect branches 2 mm high, with one verticil only, borne on slender stolons at
close intervals; each whorl of verticil on erect branches of filaments which
branch from about the middle; branching dichotomous, terminating as determinate
branchlets; rhizoids scattered irregularly along stolon; siphonaceous and appear
like Chara to the unaccustomed eyes.

Habitat:
Attached to floating net cages and as epiphyte to other large seaweed.

Plant live alone, reach up to 12 cm in height, ftesh green in colour when ftesh,
creamy or greenish in colour upon drying, calcification medium, bulb-like
holdfast, 4 - 5 cm in length. Lower part of the segment is compressed, square
and subcuneate, arising ftom single surface, 2 or more branches that is
isolated. As a whole the segment looks like fan, branching looks bigger and
flat, compressed, 1 - 3 mm thick, usually it is flabellate but sometimes with
four angles.

Plants white to green, heavily calcified, growing as massive clumps, young
plants with a single holdfast but holdfast later obscured by secondary
attachments and random branching. The segments are three lobed, but not as
pronounced as in H. incrassata: segments 3 - 10 mm wide. Basal cuneate segments ftom invisible stipe.

Thalli erect, up to 11 cm tall, excluding the bulbous holdfast which may extend
to 5.5 cm long; bright green when fresh, greenish to cream when dried; basal
portion may consist of one or three fused segments, all together forming a
fan-shaped stipe &om which arise four to eight daughters segments; each
supporting a series of segments that are moderately calcified with ribbed
surfaces; segments vary in shape; cuneate to subcuneate, flabellate to reniform,
upper margins undulate, sinuate to deeply lobed. This species inhabits shallow,
intertidal areas, growing on sand or on muddy-sandy substrates associated with
other seaweed and seagrass species.

The blade is firm and smooth, not obviously fIlamentous. Filaments of the blade
produce a cortex of densely branched surface fIlaments, fIlaments have truncate
of thickened end walls. Blades often proliferous from the face or margin.

Plants form dark green mats often reaching 3 - 5 cm thick and of indefmite
extent. Thalli are composed of filaments of multi nucleate cells approximately 1
mm in diameter.
Filaments are somewhat stiff and turgid. Branching is irregular and proliferous.
Branches are generally short and stubby.

The brown algae have-plenty of xanthophyll pigments,
especially fucoxanthin, which gives them their distinctive brown coloration. The
other pigments present in their cells are chlorophylls a and c and carotenes.
Their chloroplasts have thylakoids grouped into bands of three. Their cell wall
is composed of cellulose and alginic acid as well as other polysaccharides.
Laminarin and mannitol are the food reserve of this group.

Reproduction among the brown algae is both sexual and
asexual. All motile reproductive cells are laterally biflagellated except in the
members of Dictyotales where the male gametes are uniflagellated and the female
gametes non-flagellated. An alternation of the gamete-producing phase (gametophytic
generation) and spore-producing - phase (sporophytic generation) occurs in most
members of this group except in the Fucales where there is no alternation of
generation. Vegetative propagation through fragmentation of the thallus may also
take place at the juvenile or adult stage. There are also the formation and
abscission of special reproductive branches known as propagula.

Plants erect, often entangled, 3-7 cm high, with flat, dichotomous branches
about 3mm broad in the lower portions; fronds narrowing abruptly to 0.1-0.2 mm
in the upper portions; branches forming angles of90° and 1200 ; tips usually
blunt or rounded.
The presence of very narrow linear segments together with wider ones in the same
thallus is characteristic of this species.

Thalli erect, bushy to 15 cm tall, greenish brown, attached by means of discoid
holdfast; branching repeatedly alternate-dichotomous forming rounded axil;
branches strap-shaped, 2.5-10 mm across, widest just below the forking,
narrowest at the terminal portions; segments between the dichotomies decrease in
length from base to the distal end of the thallus; apices of the terminal
segments rounded to obtuse when young, dentate or aculeate when mature. Outer
margins of the blades entire.

Thallus is a fan or kidney-shaped blade arising from a narrow
type, brown in colo\J to 5.0 cm across the blade. The blade is distromatic
throughout. The margin 0 blade is curled inward; blade may be tom from wave
action. Sori occur above concentric rows of hair.